Well, I've got both. To be honest I haven't used P7 on my G5 dual 2GHz (other than big renders) much but it certainly seemed to be fine. I mostly use my poor old G4 iBook 1.2GHz with 768MB RAM (mainly because it's always with me wherever I go) and P7 seems to render better but the whole thing is certainly more sluggish than P6 was. I haven't had any problems with Logic so I'm not sure what the problem is there... If you're a musician you should just have it ;) In a nutshell: P7 on G5 = Good (especially with dual processors and plenty of RAM) P7 on G4 = Slooooow P7 on Intel = Probably better than G5, but I don't know as I can't afford to buy one to find out :( Just send me a MacBook Pro and I'll be glad to do the testing for you :D